<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
<form>
    籍贯：
    <select>
        <!-- selected="selected" 放进option 里代表默认选中 ed代表过去式的意思 -->
        <option>地球</option>
        <option>水星</option>
        <option>月球</option>
        <option>火星</option>
        <option selected="selected">地王星</option>
    </select>
</form>
    
</body>
</html>